The invention relates to a refrigerant accumulator for a vehicle air-conditioning system. In particular, it concerns a refrigerant accumulator for receiving and releasing a liquid refrigerant within the scope of a cooling process of a vehicle air-conditioning system having special properties for high operating pressures, especially for the operation of a vehicle air-conditioning system that utilizes CO2 as the refrigerant.
It is known that, in the dynamic operation of a vehicle air-conditioning system, a non-evaporated, liquid refrigerant can appear on the outlet side of an evaporator; this refrigerant must be kept in interim storage and only supplied to the downstream components, such as intermediate heat exchangers, in small quantities to avoid damaging the compressor. A corresponding refrigerant accumulator is described in, for example, U.S. Pat. No. 5,245,836 by Lorentzen et al., issued on Sep. 21, 1993.
The known, described refrigerant accumulators are cylindrical, however, and are produced with special connector ends, such as arched dished ends. This construction results in a large mass and large dimensions with high operating pressures. Furthermore, numerous welded seams must be created for securing the connector end; it has been seen that, due in part to the large number of these seams, they may have weak points. Large dimensions and masses also preclude the use of these refrigerant accumulators in compact vehicles.
It is therefore the object of the invention to provide a refrigerant accumulator of the type mentioned at the outset, which is highly resistant to pressure and has a low mass, and can be produced simply with technically simple means.
This object is accomplished by a refrigerant accumulator of the type mentioned at the outset, which comprises an upper and a lower half-shell that are connected to one another by a welded seam.
This not only reduces the dimensions and the mass of a refrigerant accumulator, but also shortens the production time, because only a single welded seam must be created.
Because only one welded seam is to be created, the risk of a weak point in the welded seam decreases; a single welded seam can be checked significantly more simply and quickly.
The two half-shells can be concave or semi-spherical, and vertically superposed.
The concave or semi-spherical embodiment of the lower half-shell advantageously allows separated liquid to run together in the lowest point of the container.
The two half-shells can be made of plastic or metal; metal half-shells can withstand a higher pressure.
In an advantageous embodiment of the invention, the upper half-shell has a separator pipe, which is guided through the wall of the upper half-shell and, on an intake side, is provided with a pipe connector located outside of the upper half-shell.
If the end of the separator pipe is bent laterally inside the refrigerant accumulator, it is advantageously possible to convey the medium entering in jet form to the inside wall of the refrigerant accumulator, and separate the liquid components there. This also prevents separated liquid in a li quid sump from foaming due to the incoming jet flow.
If the upper half-shell also has a pipe connector for a mixing pipe on an outlet side, with the pipe extending through the lowest region of the lower half-shell and back into the upper half-shell, it is no longer possible for the incoming medium to enter the mixing pipe.
If the mixing pipe in the lowest region of the lower half-shell has at least one pipe bore that leads to the wall of the lower half-shell, it is possible to suction off virtually all of the separated refrigerant.
In a further advantageous embodiment, the mixing pipe has at least one bore above the maximum anticipated level of a liquid sump. This assures the known accumulator function of forming a mixture of liquid and gaseous media at the outlet.
In accordance with a further advantageous embodiment of the invention, the respective diameters of the at least one pipe bore and the at least one bore are dimensioned such that a mixing ratio of the liquid mass drawn from the liquid sump to the gas mass that has been flowed through is formed virtually independently of the mass throughput through the mixing pipe.